The US Army Edgewood Chemical Biological Center is the leader in development of military systems for chemical and biological defense, in collaboration with all Services, other Government laboratories, academia, and industry. Chemical and biological optical sensing principles, unique capabilities, state-of-the-art sensors, and emerging technologies will be discussed. Exciting new results will be presented on standoff biodiscrimination using infrared (IR) depolarization lidar and long-wave IR (LWIR) lidar.
The US Army Edgewood Chemical Biological Center (ECBC) is the leader in development of military systems for chemical and biological defense, in collaboration with all Services, other Government laboratories, academia, and industry. Chemical and biological optical sensing principles, unique capabilities, state-of-the-art sensors, and emerging technologies will be discussed. In order to acquire highly quantified data, study the effects of variables such as particle size distribution on backscatter coefficients, perform iterative aerosol algorithm development, and characterize breadboards, a novel "windowless" Vortex Chamber utilizing air curtains was developed and built at ECBC. The chamber has been successfully shown to contain a cloud of known size, concentration, and particle size distribution for 10-15 minutes. Near-term plans are focused on characterization of breadboards for standoff bio discrimination and deducing absolute backscatter coefficients from Vortex Chamber data.
Laser Interrogation of Surface Agents (LISA) is a UV-Raman technique that provides short-range standoff detection and identification of surface-deposited chemical agents. ITT Industries, Advanced
Engineering and Sciences Division, is currently developing and expanding the LISA technology under several programs that span a variety of missions for homeland defense. We will present and discuss some of these applications, while putting in perspective the overall evolution undergone by the technique within the last years. These applications include LISA-Recon (now called the Joint Contaminated Surface Detector--JCSD) which was developed under a cost-sharing arrangement with the U.S. Army Soldier and Biological Chemical Command (SBCCOM) for incorporation on the Army’s future reconnaissance
vehicles, and designed to demonstrate single-shot on-the-move measurements of chemical contaminants at concentration levels below the Army's requirements. In parallel, LISA-Shipboard is being developed to optimize the sensor technique for detection of surface contaminants in the operational environment of a ship. The most recently started activity is LISA-Inspector that is being developed to provide a transportable sensor in a 'cart-like' configuration.
A UV fluorescence lidar system for the remote detection of bioaerosols has been built and tested. At the heart of the UV- LIDAR Fluorosensor system are a 200 mJ quadrupled Nd:YAG laser at 266 nm and a 16-inch Cassagrain telescope. Operating on three data collection channels, the UV lidar is capable of real time monitoring of 266 nm elastic backscatter, the total fluorescence between 300 and 400 nm, and the dispersed fluorescence spectrum (using a small spectrograph and gated intensified CCD array). Our goal in this effort was to assess the capabilities of biofluorescence for quantitative detection and discrimination of bioaerosols. To this end, the UV-LIDAR Fluorosensor system was tested against the aerosolized bacterial spore Bacillus subtilus var. niger sp. globiggi (BG) and several likely interferences at several ranges from approximately 600 to 3000 m. Our tests with BG indicate a detection limit of approximately 500 mg/cubic meter at a range of 3000 m.
Until quite recently the ability to detect and discriminate aerosolized micro-organisms at long range using the laser induced fluorescence (LIF) technique has met with limited success. The lasers which met our logistic requirements had insufficient energies to propagate through the troposphere and excite a target organism. The detectors, though sensitive enough, did not allow us to see a spectral distribution of the fluorescence return. Advances in laser and detector technology has now brought us higher energy, solid state lasers, and very sensitive array detectors. Using this new technology we built and tested an ultraviolet LIDAR against various interferents and a micro-organic contaminant. In this paper we describe the system and method used to detect and discriminate an aerosolized micro-organism at ranges up to 3 kilometers, and the results of this effort.